"The choice to stay close to their partner over accessing food demonstrates how an individual bird's decisions in the short term, which might appear sub-optimal, can actually be shaped around gaining the long-term benefits of maintaining their key relationships," says lead author Josh Firth from the University of Oxford in the UK.

"Therefore, even in wild animals, an individual's behaviour can be governed by aiming to accommodate the needs of those they are socially attached to."

Staying with their partner also meant that they became better acquainted with other members of the flock.

Having this additional support network could help them access food by other means such as scrounging, the authors report.